Table 2 Odds of farm equipment crashes occurring on Iowa road segments calculated using Logistic Regression
Farm equipment crash | ||
|---|---|---|
cOR (95% CI)a | aOR (95% CI)b | |
Road characteristics | ||
Traffic volumec | ||
0–30 | Ref | Ref |
31–101 | 1.93 (1.54–2.40) | 2.00 (1.60–2.49) |
102–360 | 1.69 (1.35–2.12) | 3.76 (2.97–4.77) |
361–1250 | 3.26 (2.66–4.00) | 7.43 (5.90–9.34) |
1251+ | 3.88 (3.17–4.74) | 7.00 (5.38–8.85) |
Speed limit (mph)d | ||
< 35 | Ref | Ref |
35–45 | 3.59 (2.75–4.68) | 3.03 (2.30–3.99) |
50–60 | 4.64 (3.92–5.49) | 8.05 (6.59–9.84) |
65+ | 4.02 (2.87–5.64) | 3.52 (2.42–5.14) |
Road typee | ||
Interstate | 0.59 (0.26–1.31) | 0.60 (0.27–1.35) |
US route | 4.53 (3.77–5.44) | 4.86 (3.99–5.91) |
Iowa route | 5.70 (4.80–6.78) | 5.98 (4.97–7.20) |
FTM routef | 4.70 (4.14–5.34) | 4.67 (4.11–5.32) |
Local route | Ref | Ref |
Surface type | ||
Paved | Ref | Ref |
Unpaved | 0.65 (0.58–0.73) | 0.97 (0.86–1.11) |
Road widthg | ||
mean(sd) | 0.95 (0.91–0.99) | 0.90 (0.86–0.94) |
Shoulder widthg | ||
mean(sd) | 1.44 (1.39–1.49) | 0.94 (0.89–1.00) |